The power switchgear provided in a substation or a switching station has a circuit breaker configured to interrupt a current at a short-circuit fault of a power system, a disconnector configured to switch the power system, and an earthing switch configured to earth a high-voltage conductor during inspection or the like. Examples of conventional technologies on the power switchgear include those described in patent document 1 to patent document 4.
The patent document 1 discloses a gas-insulated composite switchgear including a circuit breaker, a disconnector, and an earthing switch. The circuit breaker is accommodated in an interrupting unit container filled with an insulating gas. The disconnector and the earthing switch are accommodated in the same container filled with the insulating gas on a side opposite to a side close to the interrupting unit. An operating mechanism is separately provided for each of the circuit breaker, the disconnector, and the earthing switch.
The patent document 2 describes an example of a hydraulic operating mechanism of a sealed switchgear having a circuit breaker, a disconnector, and an earthing switch. In the hydraulic operating mechanism of the patent document 2, one hydraulic generator is provided in common with the circuit breaker, the disconnector, and the earthing switch, and is connected via an electromagnetic valve to a hydraulic cylinder that drives each of the circuit breaker, the disconnector, and the earthing switch.
In the conventional technologies, operating mechanisms for individually driving the circuit breaker, the disconnector, and the earthing switch are separately provided for configuring the switchgear including such devices.
Furthermore, patent document 3 and patent document 4 describe a spring operating mechanism that accumulates power in a spring and a hydraulic operating mechanism that stores power in an accumulator, respectively, each of which is used for operating the conventional circuit breaker.